The invention concerns a recoiler for recoiling strip-shaped materials, especially for slitting and recoiling machines for the longitudinal slitting of chiefly thin rolled strip made of metal and steel into individual strips and the recoiling of the individual strips into strip coils, with a core shaft that can be driven by a motor, clamping devices for securing the strip-coil coiling sleeves, which can be slid onto and pulled off of the recoiler, and structural components for transmitting the torque of the core shaft to the individual coiling sleeves during recoiling of the individual strips with equal or approximately equal strip tension.
The recoiling of the individual strips produced by longitudinal slitting of a rolled strip onto coiling sleeves, which are arranged on a common recoiler, involves problems arising from the nature of rolled strip. Rolled strip has different thicknesses in the center and at the edges. The center thickness is usually somewhat greater than the thickness at the two edges. Therefore, internal mechanical stresses are present in the strip between the edges and the center of the strip. When the rolled strip is slit into individual strips by a slitting machine, the internal stresses are relieved. This results in different lengths of the individual strips, i.e., the individual strips derived from the thicker central region of the rolled strip are shorter, and the individual strips derived from the thinner marginal regions of the rolled strip are longer. The different lengths and different strip thicknesses must be compensated to coil all of the individual strips with the same strip tension, if the individual strips are to be recoiled on coiling sleeves that are arranged on a common recoiler, and if all of the individual strips are to be recoiled equally tightly.
To recoil several coils of strip-shaped materials on a recoiler of the generic type described in EP 0 863 101 A1, a core shaft equipped with frictional elements is used to kinematically uncouple the individual strip coils and to apply well-defined torques. The goal of this is to load all of the strip coils, regardless of their particular strip widths, with specifically equal strip tension to avoid wrinkling and deformation within the slitting machine and destruction of individual strips of material.
The previously known recoiler for recoiling strip-shaped materials on coiling sleeves consists of a core shaft annularly surrounded by frictional elements and radially acting clamping devices, which, in the operating position, produce frictional engagement between friction elements driven by the core shaft and the frictional elements, by which a torque can be transmitted from the core shaft to the frictional elements, accompanied by slip. The frictional elements can move towards the outside to produce a torsionally rigid connection between the frictional elements and the coiling sleeve during operation.
The clamping devices move the frictional elements radially outward via the friction elements by means of the radial forces they apply and bring the frictional elements against the coiling sleeve to reliably ensure slip-free driving of the coiling sleeve with a certain torque. In this regard, under the influence of the radial forces of the clamping devices that act in the operating position, the torque transmitted by the friction pairing friction element/frictional element is less than the torque that can be transmitted by the friction pairing frictional element/coiling sleeve, so that a torsionally rigid drive is produced between the frictional element and the coiling sleeve.
DE 195 15 723 A1 describes a generic recoiler, which consists of a core shaft with peripherally distributed longitudinal grooves, in each of which there is an outwardly directed antifriction strip and an inflatable pressure-medium hose for moving the antifriction strip radially outward. An annular backing material is placed on the core shaft, and the antifriction strips rest against the inner surface of the backing material. The antifriction strips, which extend the whole length of the core shaft, consist either of oil-impregnated strips of felt or of an antifriction material that can release lubricant. On the outer surface of the backing material, several obliquely running, peripherally distributed bearing surfaces interact with clamping devices in the form of balls. The balls are arranged in recesses of a clamping ring in such a way that, even in the untensioned state of the recoiler, they extend slightly beyond the outer surface of the clamping ring.
At the beginning of a recoiling operation, the coiling sleeves are slipped onto the friction recoiler. Since the balls extend slightly beyond the outside of the clamping ring, the coiling sleeves are very easily slid in the axial direction onto the friction recoiler until the desired or required position is reached. The individual pressure-medium hoses have been inflated in advance, so that frictional engagement with the backing material occurs through the antifriction strips, and the backing material turns clockwise together with the rotational movement of the core shaft. This causes the balls to be pushed farther to the outside due to the oblique position of the bearing surfaces, so that, finally, the coiling sleeves are held tightly in the position they have assumed. When the friction is released, the balls return to their original position, in which they extend slightly beyond the outer surface of the clamping ring, so that the completely coiled strip can then be easily pulled off of the recoiler.
With the previously known frictional recoilers, it is difficult, especially in the case of small strip coil diameters, to transmit a large torque from the core shaft to the coiling sleeves of the individual strip coils and to achieve uniform recoiling of the individual strips of material with a constant strip tension.
The goal of the invention is to develop a recoiler of the generic type, which allows uniform recoiling of strip coils with different diameters and coil widths.
In accordance with the invention, this goal is achieved by a recoiler for recoiling strip-shaped materials, which has the features specified in claim 1.
The subclaims contain effective and advantageous modifications of the invention.
The new recoiler represents an optimum solution of the problem on which the invention is based.